This invention relates to fabric conditioning compositions containing a cellulose ether as a soil release agent. More particularly, this invention relates to the use of cellulose ethers having a low molecular weight and a high degree of methyl substitution. Fabric conditioning compositions containing the cellulose ether give soil release properties to fabrics contacted therewith, thereby rendering the fabrics easier to clean in subsequent washings.
Cellulose ethers are a well known class of materials. They are generally derived from vegetable tissues and fibers, including especially cotton and wood. The molecular weight of such cellulose ethers vary from about 19,000 to about 185,000. The molecular weight of the cellulose materials can be reduced by various means including aqueous acid hydrolysis, oxidative depolymerization, and by reaction with gaseous hydrogen chloride. For example, see U.S. Pat. No. 3,391,135, July 2, 1968, Ouno et al, and British Pat. No. 1,139,637, published Jan. 8, 1969. Changing the molecular weight of a cellulose ether necessarily affects its physical properties.
The hydroxyl groups of the anhydroglucose unit of cellulose can be reacted with various agents thereby replacing the hydrogen of the hydroxyl with the reacting agent. For example, various alkylating and hydroxyalkylating agents have been reacted with cellulose materials to produce alkyl cellulose ethers and hydroxyalkyl cellulose ethers. The degree of substitution may vary up to 3.0 since there are three available positions on each anhydroglucose unit. The kind of substitution and degree thereof also has an effect on the physical properties of the cellulose material.
Fabric conditioning compositions containing various soil release agents are known. For example, see U.S. Pat. No. 3,920,561, DesMarais, issued Nov. 18, 1975 and U.S. Pat. No. 3,928,213, Temple et al., issued Dec. 23, 1975. While certain of the prior art cellulose ethers have been able to efficiently and effectively deposit upon fabrics and thus provide a soil release benefit, there are consequent negatives involved. It has been found that deposition of certain of the prior art cellulose ethers on fabrics causes a negative in particulate soil removal. More specifically, when such treated fabrics are subsequently stained with a particulate soil, e.g. clay, and washed, the stain is more difficult to remove. It is believed the cellulose ether provides a bonding site for the particulate soil, thus causing its removal to be more difficult.
It is an object of this invention to provide fabric conditioning compositions which impart soil release properties to fabrics without causing particulate soil removal negatives.
Still another object of this invention is to provide fabric conditioning compositions which impart oily soil release properties to fabrics and are formulated to be added to the washing machine.
These and other objects of the invention will become apparent from the description to follow.
As used herein, all percentages and ratios are by weight unless otherwise indicated.